Adafruit PowerBoost 500 Basic
Created by lady ada
Last updated on 2018-08-22 03:41:42 PM UTC
Overview
PowerBoost is the perfect power supply for your portable project! (https://adafru.it/dFq)This little DC/DC boost
converter module can run from 1.8V batteries or higher, and convert that voltage to 5.2V DC for running your 5V
projects. Like our popular 5V 1A USB wall adapter (https://adafru.it/duP), we tweaked the output to be 5.2V instead of a
straight-up 5.0V so that there's a little bit of 'headroom' for long cables, high draw, the addition of a diode on the
output if you wish, etc. The 5.2V is safe for all 5V-powered electronics like Arduino, Raspberry Pi, or Beagle Bone while
preventing icky brown-outs during high current draw because of USB cable resistance.
© Adafruit Industries https://learn.adafruit.com/adafruit-powerboost Page 3 of 10
The PowerBoost 500 (https://adafru.it/dFq) has at the heart a TPS61090 boost converter from TI (https://adafru.it/duQ).
This boost converter chip has some really nice extras such as low battery detection, 2A internal switch, synchronous
conversion, excellent efficiency, and 700KHz high-frequency operation. Check out these specs!
Synchronous operation means you can disconnect the output completely by connecting the ENable pin to
ground. This will completely turn off the output
2A internal switch (~2.5A peak limiting) means you can get 500mA+ from as low as 1.8V, 750mA+ from 2 NiMH
or Alkaline batteries, and at least 1000mA from a 3.7V LiPoly/LiIon battery or 3 NiMH/Alkalines.
Low battery indicator LED lights up red when the voltage dips below 3.2V, optimized for the most common
usage of LiPo/LiIon battery usage
Onboard 500mA charge-rate 'iOS' data resistors. Solder in the USB connector and you can plug in any iPhone or
iPod for 500mA charge rate. Not suggested for iPad (which really needs 1A charge rate).
Full breakout for battery in, control pins and power out
90%+ operating efficiency in most cases (see datasheet for efficiency graphs), and low quiescent current: 5mA
when enabled and power LED is on, 20uA when disabled (power and low batt LED are off)
© Adafruit Industries https://learn.adafruit.com/adafruit-powerboost Page 4 of 10
Great for powering your robot, Arduino project, single-board-computer such as Raspberry Pi or BeagleBone! Each
order comes with one fully assembled and tested PCB and a loose USB A jack. If you are powering your project from
USB, solder the USB A jack in (a 3-minute soldering task). If you would like to use a terminal block, pick up a 3.5mm
2pin block here (https://adafru.it/duR) and solder to the output spot where the USB jack would go. Or dont solder
anything in for a more compact power pack.
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Pinouts
For many people, the PowerBoost can be used with just the power input and power outputs. However, we have a
couple handy breakouts so lets get started!
Power Pins
There's two power 'ports' - an input (called BAT) and an output (called 5V)
BAT - this is the battery input, it can range from 1.8V to 5V. Higher voltages will let you draw more current and in
general, are more efficient. Try to keep the wires going to this pin nice and short - 3" or less is best!
GND - this is the power ground. This boost converter is not 'isolated' - the ground input is the same as the
ground output
5V - this is the boosted output. When the board is running, the voltage will be 5.2V approximately. It may dip
down to 5V as the current draw starts to go up (over 500mA). When the board is disabled, this output is 'floating'
but you should still try not to apply a voltage to it while the board is disabled. There's a green LED connected to
this pin which will let you know when there's power output
Control Pins
There's two 'control' pins.
EN - this is the 'enable' pin. By default it is pulled 'high' to VBAT. To turn off the booster, connect this pin to
ground. The switch can be as small as you like, it is just a signal. Contrast this to an inline power switch which
would have to be able to handle up to 2A of current! When the chip is disabled the output is completely
Using a bench-top supply or long wires can add too much inductance to the input of the boost converter and
destroy it! We really do recommend using Lipoly batteries with short wires
© Adafruit Industries https://learn.adafruit.com/adafruit-powerboost Page 7 of 10
disconnected from the input.
LBO - not a leveraged buy out! this is the Low Battery Output. By default it is pulled high to BAT but when the
charger detects a low voltage (under 3.2V) the pin will drop down to 0V. You can use this to signal when its time
to shut down or alert the user that the battery is low. There is also a red LED connected to this pin.
LEDs
There are two onboard LEDs. The Green LED sits next to the USB connector socket, and indicates the 5V output
power state. The Red LED is next to the battery JST port and indicates when the battery voltage is below 3.2VDC
Battery and USB connection
You can connect a battery to the breakout strip or to the JST connector. All of Adafruit batteries come with JST cables
that will plug in nicely. Watch the polarity of the cable! the + and - markings next to the JST will let you know which
way is which.
The USB connector can be soldered on to create a portable 'USB power pack'. The two data lines on USB have
resistor dividers that match Apple charger values so that you can plug any iOS device in to charge. 99% of other
phones, devices and tables are totally cool with these resistors as well. You can always short the D+ and D- lines if you
happen to have a phone that wants shorted data lines.
If you don't want a USB connector attached, there are two holes that are designed for a 3.5mm spaced terminal block
(not included)
© Adafruit Industries https://learn.adafruit.com/adafruit-powerboost Page 8 of 10
Downloads
Datasheets & Files
TPS61090 datasheet (https://adafru.it/duS)(the DC/DC boost control chip used)
Fritzing object in Adafruit Fritzing library (https://adafru.it/aP3)
EagleCAD PCB files in GitHub (https://adafru.it/r4D)
Schematic
Fabrication Print
Dimensions in Inches
© Adafruit Industries https://learn.adafruit.com/adafruit-powerboost Page 9 of 10
© Adafruit Industries Last Updated: 2018-08-22 03:41:37 PM UTC Page 10 of 10
